CN103326237B - Method for designing two-dimensional stack of high power semiconductor laser device with symmetrical light beam quality - Google Patents

Abstract

The invention provides a method for designing a two-dimensional stack of a high power semiconductor laser device with symmetrical light beam quality. The two-dimensional stack is parallelly packaged by n bars in the fast axis direction, each bar comprises m semiconductor laser units, and both n and m are natural numbers larger than or equal to 1. After dead zones are removed, the number n of the needed bars and the number m of the semiconductor laser units included in each bar are determined according to target light beam integrable parameters of the laser device, therefore, the light beam quality in the slow axis direction of the two-dimensional stack of the semiconductor laser device is almost equal to the light beam quality in the fast axis direction of the two-dimensional stack, namely the light beam quality is directly symmetrical in the two directions, and an optical shaping system is no longer needed. According to the design method, the high power semiconductor laser device with symmetrical light beam quality and high light beam quality can be directly acquired, when optical fibers are coupled or focused, the complex optical shaping system is no longer needed, simple focusing optical elements are directly used, and therefore the whole system becomes simple and efficient.

Description

The high-power semiconductor laser two dimension stack design method of beam quality symmetry

Technical field

The present invention relates to semiconductor laser field, specifically a kind of high-power semiconductor laser two dimension stack design method of beam quality symmetry.

Background technology

High power semiconductor lasers, due to advantages such as its volume are little, efficiency is high, the life-span is long, is widely used in processing, the every field such as medical, military.Especially, the multikilowatt semiconductor laser of high brightness has shown and has replaced kilowatt level optical fiber laser and CO ₂laser carries out the welding of metal material.More the semiconductor laser of high brightness can be directly used in the cutting of material.

At present, round obtaining brightness, high-power fiber laser, based on polarization coupled and wavelength coupling, development has gone out multiple coupling and has closed bundle technology.Such as application number is in the Chinese invention patent of 201010597864.8, provides and uses the dual wavelength then polarization coupled that is coupled to realize the method that four semiconductor laser arrays close bundle.Application number is the fiber-optic coupling method providing a kind of many single tubes light beam space parallel arrangement in the Chinese invention patent of 200910207824.5.Application number is propose the conjunction bundle being realized four semiconductor lasers by polarization coupled and wavelength coupling in the Chinese invention patent of 200810051211.2.Application number is provide a kind of different polarization states based on Same Wavelength in the Chinese invention patent of 201010174581.2 in conjunction with the space optical coupling structure realizing multiple single-tube laser arranged in parallel.Obviously, in above-mentioned that mention or similar invention, used be all multiple single tube or multiple semiconductor laser array coupling and close bundle, the laser power therefore finally obtained and beam quality depend on laser power and the beam quality of used semiconductor laser unit.

How to obtain the semiconductor laser unit aspect of high power, high light beam quality, current universal method is based semiconductor Laser One-dimensional bar bar (diode laser bar), in conjunction with optical shaping technology (beam-shaping) or be called light beam rearrangement technology (beam re-arrangement), obtain the Laser output of beam quality symmetry.The power limited of this method, in the power of single bar bar, generally only has tens of watts.Another kind method is that to be similar to application number be the patent of invention of 200910207824.5 and the patent of invention of 200310118154.2, namely uses multiple single tube to carry out space parallel arrangement and then focuses on coupling.The power limited of this method, in the single tube number that can arrange, generally also only has tens of watts.

Obtain multikilowatt Laser output, mode is that multiple one dimension bar bar encapsulates in the other directions side by side the most easily, and so-called two-dimentional storehouse (Stack).Typical bar bar structure and the characteristics of luminescence are as shown in Figure 1.The semiconductor laser unit 11 that bar bar is launched by the edge of multiple spacing 500 μm forms, and commercial is the arrangement being less than 10mm substantially at present.The length of illumination that each semiconductor laser unit 11 (is parallel to the direction of p-n joint) on slow-axis direction is 150 μm, and angle of divergence full-shape is 10 °.Between adjacent luminescence unit, non-luminous region is called that in dark space or dead band (Dead area) 12, Fig. 1, dead band 12 length is 350 μm.The luminous width of quick shaft direction (direction perpendicular to p-n joint) is 1 ~ 2 μm, and angle of divergence full-shape is 40 °, and beam quality is diffraction limit.

Fig. 2 is the structural representation of a typical two-dimentional storehouse.Spacing between each bar bar is d=1.7-1.8mm (being 1.7mm shown in figure), is also therefore about 1.7-1.8mm in the dead band that this side up distance.Visible, for typical bar bar and storehouse, the beam quality on fast axle and slow-axis direction is widely different, and the existence in dead band is greatly degrading beam quality.Therefore, high light beam quality, high-power Laser output cannot be obtained by the image optics of routine.

Beam quality usually uses M ²the factor characterizes:

$M^2=\frac{\mathrm{\π\ω\θ}}{\mathrm{\λ}}=\frac{\mathrm{\π}}{\mathrm{\λ}}\mathrm{BPP}$

Wherein, λ is wavelength, and ω is with a tight waist, and θ is the angle of divergence (half-angle).BPP=ω θ is that light beam amasss parameter (beam parameter product).Visible, for specific wavelength, beam quality can amass parameter BPP to characterize with light beam.

For the single semiconductor laser unit 11 in the bar bar shown in Fig. 1, the BPP on slow-axis direction is about:

And the BPP with the fast axle of the 980nm of the beam quality of diffraction limit is

${\mathrm{BPP}}_{980/\mathrm{fast}}=\frac{\mathrm{\λ}}{\mathrm{\π}}=\frac{0.98}{3.14}=0.312\mathrm{mmmrad}$

The thinking that the conventional semiconductor laser obtaining more than hundreds of watts high light beam qualities exports has two kinds: a kind of is the two-dimentional storehouse encapsulated based on routine, after fast and slow axis standard (removal dead band), use complicated optical shaping system to carry out shaping rearrangement, make the beam quality of fast and slow axis symmetrical.Difficulty is that required shaping system for rearranging is very complicated, is difficult to processing, and bulky, regulate difficulty; Another kind of thinking uses multiplely independently to cling to bar, is aided with shaping system for rearranging separately, then carry out conjunctions and restraint.Still there is the weakness such as device is too much, bulky, adjustment difficulty in this decorum.

Summary of the invention

The object of the invention is to the defect of the scheme solving the existing semiconductor laser about high-power and high-lighting beam quality, a kind of high-power semiconductor laser two dimension stack design method of beam quality symmetry is provided, without the need to using complicated optical shaping system to carry out shaping rearrangement after fast and slow axis standard (removal dead band), can realize high brightness, the output of powerful coupling fiber by simple focusing optical, structure is simple, handling ease.

A kind of high-power semiconductor laser two dimension stack design method of beam quality symmetry, described two-dimentional storehouse is formed by the parallel encapsulation on quick shaft direction of n bar bar, each bar bar contains m semiconductor laser unit, wherein n, m is >=natural number of 1, after going to dead band, amass parameter according to the target beam of laser and decide the number n of required bar bar and each bar bar contains the number m of semiconductor laser unit to make the beam quality on the quick shaft direction of the beam quality on the slow-axis direction of semiconductor laser two dimension storehouse and two-dimentional storehouse approximately suitable, namely beam quality is directly symmetrical in the two directions, no longer need shaping optical system.

Further, the number n of bar bar is that the target beam of laser amasss parameter and amasss parameter divided by the light beam of the fast axle of single bar bar and be multiplied by fast axle again and go dead band efficiency, and the number m of the semiconductor laser unit contained by each bar bar is that the target beam of laser amasss parameter and amasss parameter divided by the light beam of the slow axis of single semiconductor laser unit and be multiplied by slow axis again and go dead band efficiency.

Further, fast axle goes to dead band to adopt fast axis collimation lens or the optical collimation lens array containing multiple fast axis collimation device.

Further, fast axle goes to dead band to take aspheric design, and from the width of light beam of the outgoing of each fast axis collimation mirror as far as possible close to the spacing of adjacent bar bar to obtain the minimum angle of divergence, thus obtain maximum fast axle and go dead band efficiency.

Further, slow axis goes to dead band to adopt the optical collimation lens array containing multiple slow axis collimater.

Further, slow axis goes to dead band to take aspheric design, and from the width of light beam of the outgoing of each slow axis collimating mirror as far as possible close to the spacing between adjacent two semiconductor laser units to obtain the minimum angle of divergence, thus obtain maximum slow axis and go dead band efficiency.

Further, the dead band device that goes that also can be aided with other reaches the object of effectively going to dead band, as shaped mirror array, to obtain best going dead band effect.

Fast axis collimation optical lens array of the present invention and slow axis collimating optic lens array also can be integrated into a slice fast and slow axis collimator lens array further.

According to method for designing of the present invention, can directly obtain beam quality symmetry, the high power semiconductor lasers of high light beam quality, when carrying out coupling fiber or focusing on, to no longer need complicated optical shaping system, the simple focusing optical of direct use, makes whole system become simply, efficient.This laser, in conjunction with polarization coupled and wavelength coupling, can obtain the Laser output of several multikilowatts of high light beam quality (such as 25mmmrad) easily, also can realize little core optical fibers easily and export.

Accompanying drawing explanation

Fig. 1 is common semiconductor laser one dimension bar bar structure and characteristics of luminescence schematic diagram, and wherein the slow axis length of illumination of single semiconductor laser unit is 150 μm, and angle of divergence full-shape is 10 °.The luminous width of semiconductor laser unit quick shaft direction is 1-2 μm, and angle of divergence full-shape is 40 °.The spacing of adjacent semiconductor luminescence unit is 500 μm;

Fig. 2 is the structural representation of common semiconductor laser two dimension storehouse;

Fig. 3 is the high power of beam quality symmetry of the present invention, the semiconductor laser two dimension stack architecture schematic diagram of high light beam quality;

Fig. 4 is the schematic diagram that fast and slow axis collimation goes dead band optical system, and wherein, Fig. 4 (a) is plane graph, and Fig. 4 (b) is stereogram.

In figure: 10-clings to bar, 11-semiconductor laser unit, 12-dead band, 20-package module.

Embodiment

Below in conjunction with the specific embodiments and the drawings in the present invention, the technical scheme in the present invention is clearly and completely described.

The present invention proposes the method for designing of a kind of high power of beam quality symmetry, the semiconductor laser two dimension storehouse of high light beam quality, and this two-dimentional storehouse is formed by the parallel encapsulation on quick shaft direction of n (n is the natural number of >=1) individual bar bar 10.Each bar bar 10 forms containing m (m is the natural number of >=1) individual semiconductor laser unit 11.Design principle is: after going to dead band (deadarea), semiconductor laser two dimension storehouse slow-axis direction on beam quality and two-dimentional storehouse quick shaft direction on beam quality approximately suitable, when carrying out coupling fiber or focusing on, to no longer need complicated optical shaping system, directly use simple focusing optical.

Bar bar 10 number n depend on the target beam quality of laser and the fast axle of single bar bar 10 beam quality and bar bar 10 between dead band 12 go dead band efficiency, further, the number n of required bar bar 10 is that the target beam of laser amasss parameter (BPP _stack) amass parameter (VPP divided by the light beam of the fast axle of single bar bar _fast) be multiplied by fast axle again and remove dead band efficiency (η _fast), namely

$n=\mathrm{Int}\left[{\mathrm{\η}}_{\mathrm{fast}}\frac{{\mathrm{BPP}}_{\mathrm{stack}}}{{\mathrm{BPP}}_{\mathrm{fast}}}\right]$

What the number m of the semiconductor laser unit 11 contained by each bar bar 10 depended on dead band between the semiconductor laser unit of the target beam quality of laser and the beam quality of single semiconductor laser unit slow axis and bar bar goes dead band efficiency, further, the number m of the semiconductor laser unit 11 contained by each bar bar 10 is that the target beam of laser amasss parameter (BPP _stack) amass parameter (BPP divided by the light beam of the slow axis of single semiconductor laser unit _slow) be multiplied by slow axis again and remove dead band efficiency (η _slow), namely

$m=\mathrm{Int}\left[{\mathrm{\η}}_{\mathrm{slow}}\frac{{\mathrm{BPP}}_{\mathrm{stack}}}{{\mathrm{BPP}}_{\mathrm{slow}}}\right]$

Wherein in an embodiment, if its target designs the axial light beam of speed to amass parameter (BPP _stack) be not more than 30mmmrad, the 500W semiconductor laser of wavelength 980nm two dimension storehouse, then typical one dimensional bar bar structure chart is as shown in Figure 1 known, and the light beam of single semiconductor laser unit on fast axle and slow-axis direction amasss parameter and be respectively:

${\mathrm{BPP}}_{\mathrm{fast}}=\frac{\mathrm{\λ}}{\mathrm{\π}}=\frac{0.98}{3.14}=0.312\mathrm{mmmrad}$

In general, use conventional fast and slow axis collimating array as shown in Figure 4, fast axle goes the efficiency in dead band to reach 70%, and slow axis goes dead band efficiency to be greater than 50%, namely

η _fast＝70％

η _slow＝50％

Therefore, required bar number n is:

$n=\mathrm{Int}\left[{\mathrm{\η}}_{\mathrm{fast}}\frac{{\mathrm{BPP}}_{\mathrm{stack}}}{{\mathrm{BPP}}_{\mathrm{fast}}}\right]=\mathrm{Int}[70\%\×\frac{30\mathrm{mm}\·\mathrm{mrad}}{0.312\mathrm{mm}\·\mathrm{mrad}}]=67$ (bar)

Semiconductor laser unit number m contained by each bar bar is:

$m=\mathrm{Int}\left[{\mathrm{\η}}_{\mathrm{slow}}\frac{{\mathrm{BPP}}_{\mathrm{stack}}}{{\mathrm{BPP}}_{\mathrm{slow}}}\right]=\mathrm{Int}[50\%\×\frac{30\mathrm{mm}\·\mathrm{mrad}}{6.54\mathrm{mm}\·\mathrm{mrad}}]=2$ (individual)

Therefore, structural design as shown in Figure 3 can be obtained, namely 67 bar of the one dimension at a distance of 1.8mm bars 10 are used, each bar bar 10 containing 2 length of illumination be 150 μm, the semiconductor laser unit 11 of spacing 500 μm, remove dead band array in conjunction with fast and slow axis collimation that is conventional, aspheric design, the light beam that can obtain fast and slow axis amasss the semiconductor laser two dimension storehouse that parameter is all not more than 30mmmrad.

The luminous power P of common above-mentioned single semiconductor laser unit _sbe not less than 4W, then the exportable total laser power of this two-dimentional storehouse is:

P＝mnP _s＝67×2×4＝536W

Visible, according to method for designing of the present invention, can design easily light beam amass parameter be not more than 30mmmrad, the 500W semiconductor laser of wavelength 980nm two dimension storehouse.Use simple focusing system, just can realize the optical fiber output of core diameter 300 μm, numerical aperture 0.22.In conjunction with wavelength coupling and polarization coupled, the optical fiber that can realize thousands of watts 300 μm easily exports.

The above; be only the specific embodiment of the present invention, but protection scope of the present invention is not limited thereto, anyly belongs to those skilled in the art in the technical scope that the present invention discloses; the change that can expect easily or replacement, all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of claim.

Claims (7)

1. the high-power semiconductor laser two dimension stack design method of a beam quality symmetry, described two-dimentional storehouse is formed by the parallel encapsulation on quick shaft direction of n bar bar, each bar bar contains m semiconductor laser unit, wherein n, m is >=natural number of 1, it is characterized in that: after going to dead band, amass parameter according to the target beam of laser and decide the number m that the number n of required bar bar and each bar bar contain semiconductor laser unit, to make the beam quality on the quick shaft direction of the beam quality on the slow-axis direction of semiconductor laser two dimension storehouse and two-dimentional storehouse suitable, namely beam quality is directly symmetrical in the two directions, no longer need shaping optical system.

2. the high-power semiconductor laser two dimension stack design method of beam quality symmetry as claimed in claim 1, it is characterized in that: the number n of bar bar is that the target beam of laser amasss parameter and amasss parameter divided by the light beam of the fast axle of single bar bar and be multiplied by fast axle again and go dead band efficiency, the number m of the semiconductor laser unit contained by each bar bar is that the target beam of laser amasss parameter and amasss parameter divided by the light beam of the slow axis of single semiconductor laser unit and be multiplied by slow axis again and go dead band efficiency.

3. the high-power semiconductor laser two dimension stack design method of beam quality symmetry as claimed in claim 1, is characterized in that: fast axle goes to dead band to adopt fast axis collimation lens or the optical collimation lens array containing multiple fast axis collimation lens.

4. the high-power semiconductor laser two dimension stack design method of beam quality symmetry as claimed in claim 3, it is characterized in that: fast axle goes to dead band to adopt aspheric design, and from the width of light beam of each fast axis collimation lens outgoing as far as possible close to the spacing of adjacent bar bar to obtain the minimum angle of divergence, thus obtain maximum fast axle and go dead band efficiency.

5. the high-power semiconductor laser two dimension stack design method of beam quality symmetry as claimed in claim 1, is characterized in that: slow axis goes to dead band to adopt the optical collimation lens array containing multiple slow axis collimating mirror.

6. the high-power semiconductor laser two dimension stack design method of beam quality symmetry as claimed in claim 5, it is characterized in that: slow axis goes to dead band to take aspheric design, and from the width of light beam of each slow axis collimating mirror outgoing as far as possible close to the spacing between adjacent two semiconductor laser units to obtain the minimum angle of divergence, thus obtain maximum slow axis and go dead band efficiency.

7. the high-power semiconductor laser two dimension stack design method of the beam quality symmetry according to claim arbitrary in claim 3-6, is characterized in that: go to be aided with shaped mirror array during dead band, to obtain best going dead band effect.